John Eliot Gardiner first recorded the German Requiem in 1990, one of the first discs with his then newly formed Orchestre Révolutionnaire et Romantique. That studio recording was as remarkable for Gardiner’s monumental conception of the work as it was for a certain degree of mannerism – affectation occasionally usurping affection. He returns to the work 18 years later in a live performance from Usher Hall, Edinburgh, presenting what is recognisably a similar interpretation while at the same time demonstrating a root-and-branch rethink of the work’s very sound: a reconsideration of the warp and weft of the fabric from which it is made. This is palpable right from the start: in the viol-like sonorities of the violas; in a fastidiously researched approach to portamento (there’s a corker at the beginning of ‘Wie lieblich sind deine Wohnungen’); and in a recording that is spacious enough (while not approaching the analytical clarity of the Philips disc) to let Brahms’s distinctly Germanic harp-writing glow like a halo across the whole work. Gardiner is acutely aware, too, of the importance to the Requiem’s tinta of Brahms’s finely crafted writing for the brass and timpani.

Of course, the seismic event that occurred roughly equidistant between that earlier recording and the appearance of this one was the Bach Cantata Pilgrimage. One becomes aware of the effect on a musician of undergoing the discipline of preparing what amounts to a weekly act of devotion (whether to God or to music, it doesn’t matter), and wonders to what extent this affects his response to a devotional score such as the German Requiem – not only its notes but also text, which is itself an act of devotion, for all Brahms’s agnosticism. One also wonders to what extent Gardiner at 65 is a different musician to Gardiner at 47; how his thoughts on the central message of the work have alttered over the near two decades that separate the two recordings; how the still-young firebrand of the early music movement differs from/has grown into/mellowed into the bus-pass-carrying gentleman farmer. Where that earlier recording drove inexorably forwards, this one replaces that occasional relentlessness with urgency: the final movement particularly becomes a heartfelt plea rather than a slow conclusion to a sometimes overlong work.

The soloists too add to this sense of urgency. Matthew Brook may not be the high-cholesterol baritone often favoured in classic recordings of the German Requiem but a hint of reediness in his tone seems appropriate for one yearning to know the measure of his days. Likewise, Katharine Fuge is a less creamy soprano than some great names but again the vulnerability of her tone – notwithstanding the Schwarzkopf gasp mid-phrase before the word ‘Traurigkeit’ – does not seem out of place, considering what she is actually singing about.

The star of the German Requiem, though, is always the choir. You know you’re in safe hands with the Monteverdis and the pitch-perfect top A at 2'04" (a graveyard for many a choral society) absolutely confirms it. They open proceedings with a pair of Schütz choruses setting words Brahms was to use in the Requiem two centuries later and providing the context that was such an integral part of Gardiner’s ‘Brahms: Roots and Memories’ project. Applause is omitted, allowing silent contemplation of the revelation that comes from such a minutely considered, dramatic and, in places, aptly disturbing performance.